The present invention relates generally to ergonomic equipment for protecting hands and wrists, and more specifically to a protective pad for protecting the hands and wrists during bicycling and other activities requiring hand and wrist protection.
Hand and finger discomfort and numbness caused by irritation to the ulnar nerve and/or to the median nerve are symptoms experienced by many cyclists. These symptoms can often be alleviated by wearing padded gloves and by frequently changing hand positions on the handlebars. For some cyclists, however, hand pain and numbness is a recurring problem despite these preventative measures. This condition (particularly as it affects the ulnar nerve, which controls sensation to the ring and little fingers) is sometimes referred to as xe2x80x9chandlebar palsyxe2x80x9d and in serious cases can require medical intervention.
The pain and numbness is typically caused by pressure against the nerve as a result of the rider placing much of his or her upper body weight on the hands when leaning forward in a normal riding position. Riding on rough roads or off-road can exacerbate the problem because of the vibration and shock transmitted to the hands during such riding. Moreover, xe2x80x9croad bendxe2x80x9d handlebars common to road racing style bicycles, which extend outward from the handlebar stem and then bend forward and downward, can result in pressure to both the ulnar and median nerves depending on the rider""s hand position. When a cyclist is grasping the straight top section of road handlebars, the handlebar will be running across the palm and the pressure will be directed mostly against the ulnar nerve. However, when a rider is grasping the brake hoods, the handlebar will usually be running across the valley at the base of the palm and over the wrist crease, potentially causing irritation to the median nerve. In addition, the hand position on the brake hoods can cause discomfort in the area between the thumb and forefinger and along the lower side of the forefinger.
Padded cycling gloves (usually in combination with padded handlebar tape) are widely used by cyclists to reduce hand discomfort while cycling. However, such gloves have significant limitations that prevent them from being an adequate solution for many riders. One limitation is the padding itself, which typically is a thin piece of soft foam or gel material that provides some cushioning and vibration damping, but is limited in its effectiveness by the thinness of the material. Such gloves also lack any stiffener inserts that would cover the palm and help to distribute localized pressure across a wider area of the palm. Furthermore, because the padding in cycling gloves does not extend proximal of the base of the palm or around the lower part of the forefinger (above the knuckle), these gloves offer little or no protection to the wrist area or forefinger when a cyclist""s hands are grasping the brake hoods on traditional road-style handlebars.
Examples of gloves similar in style to cycling gloves that are designed to relieve pressure to the median nerve are disclosed in U.S. Pat. No. 4,850,341 to Fabry, et al. (1989) and U.S. Pat. No. 5,214,799 to Fabry (1993). U.S. Pat. No. 6,098,200 to Minkow, et al. (2000) discloses a cycling glove with a cushioning pad that covers the wearer""s hypothenar eminance and is intended to provide enhanced protection for the ulnar nerve.
Industrial anti-vibration and impact gloves, like cycling-specific gloves, also suffer from a variety of drawbacks. The visco-elastic polymer inserts commonly used in industrial safety gloves to reduce vibration and absorb shock lack the rigidity needed for effective distribution of pressure across the palm. Industrial anti-vibration gloves also have the disadvantages of being relatively heavy and uncomfortable in warm weather, as well as being comparatively expensive.
For those who suffer from carpal tunnel syndrome, a number of wrist support products are widely available that are designed to prevent or alleviate the symptoms by maintaining the hand in a xe2x80x9cneutralxe2x80x9d position. These supports will often use one or more rigid or semi-rigid stabilizing stays that extend from the palm to below the wrist and resist any downward bending of the hand. While the palmar stays help to distribute pressure exerted against the wrist, they restrict the wrist movement needed for activities such as cycling, where a rider must be able comfortably to change hand positions on the handlebar, squeeze the brake levers, and grasp a water bottle. In addition, such wrist supports lack a palmar pad for protecting the ulnar nerve. Examples of wrist supports for the prevention of carpal tunnel syndrome are disclosed by U.S. Pat. No. 5,267,943 to Dancyger (1992), U.S. Pat. No. 5,397,296 to Sydor, et al. (1995), U.S. Pat. No. 5,538,501 to Caswell (1996), U.S. Pat. No. 5,928,172 to Gaylord (1999), and U.S. Pat. No. 6,024,715 to Maxwell (2000).
U.S. Pat. No. 4,617,684 to Green, et al. (1986) discloses a flexible palm pad specifically designed to be worn inside a baseball glove or catcher""s mitt. The pad has a leather covering on one side and a shock absorbing material on the other side and is held against the palm by two loops, one of which encircles the forefinger and the other the back of the hand. This pad is configured to cushion the distal portion of the palm that is often impacted from catching a baseball, but does not provide protection for the wrist, forefinger, or the saddle between the thumb and forefinger.
U.S. Pat. No. 5,081,715 to Mascia (1992) shows a multiple-layer palm pad assembly that is comprised of a base layer patch of flexible material that extends from the palmar crease to the base of the palm and covers the entire width of the palm including the area at the base of the thumb. The protector is held in place by a pair of straps that extend in opposite directions from opposite edges of the patch and that are secured together around the back of the hand. One or more layers of coextensive, resilient pad material, such as neoprene foam, are then releasably secured to the base layer by means such as hook and loop fasteners. One significant shortcoming of this pad assembly for cycling is that it does not protect the wrist area at the base of the palm, the saddle area between the thumb and forefinger, or the lower part of the forefinger. In addition, the resilient pad material of the assembly lacks the rigidity needed to distribute the localized pressure on the hands resulting from holding the handlebars while leaning forward for extended periods.
In contrast to the above palmar pads, U.S. Pat. No. 5,771,901 to O""Brien (1998) discloses a relatively rigid palmar support that is designed to protect the palm when gripping a bicycle handlebar. The support covers the area of the palm extending from just distal of a distal wrist crease to the proximal side of a palmar crease and from the ulnar side of the hand to a contoured thumb saddle. The thumb saddle curves from the base of the thumb upwardly to an edge portion between the first and second joints of the thumb. The thumb saddle then curves to follow the curvature of the webbed area between the thumb and forefinger when the hand is in a partial gripping position. The palmar support is preferably molded from a material sufficiently rigid to support the rider""s weight on the handlebars without substantial flexing. The support is disclosed both as an insert for a cycling glove and as a stand-alone support that is secured by means of a strap that encircles the back of the hand.
The O""Brien ""901 palmar support suffers from several drawbacks that significantly limit its versatility. Because it is a molded and relatively rigid plate, it may be uncomfortable to wearers whose hand shape departs from the shape of the mold. Moreover, because it covers the padded area at the base of the thumb, the support would substantially restrict the mobility of the thumb. The rigid form of the support is not well suited to traditional road handlebars, because it does not allow a variety of hand positions on the brake hoods. The thin, rigid edges of the support would also tend to limit the hand flexibility necessary for easy shifting and braking and would tend to be uncomfortable in the gloveless version. The disclosed palmar support does not protect the proximal portion of the forefinger, nor does it offer protection proximal to the distal wrist crease.
U.S. Pat. No. 5,826,276 to Garceau-Verbeck (1998) discloses a hand covering intended to protect the hand from blisters and enhance the wearer""s grip during activities such as playing golf and tennis. It includes a flexible palm covering having a dart to accommodate the hump at the heel of the hand and is secured to the hand by a wrist anchor strap, a retaining band that crosses the back of the hand, and optional finger loops. The disclosed grip enhancer is not designed to provide protection from the prolonged pressure and vibration commonly experienced during cycling on the areas of the wrist, palm, forefinger, and webbing between the thumb and forefinger. Furthermore, the separate wrist anchor strap completely encircles the wrist, which prevents the lower portion of the hand covering from moving freely and sliding over the wrist when the hand is moved side to side in the same plane as the forearm. Such radial hand movement, particularly when combined with an inward movement of the hand, can cause the hand covering to bunch up at the base of the palm. Adding a layer of cushioning material to such a hand covering will only exacerbate this bunching problem.
The present invention provides a comfortable, lightweight, and inexpensive pad for protecting the ulnar and median nerves during cycling and other activities where those nerves are subjected to prolonged pressure and/or to vibration and impact. The pad of the present invention covers the saddle between the thumb and forefinger as well as the lower portion of the forefinger, which are sensitive areas left largely unprotected by the prior art. The present invention also discloses a protective pad comprised of two layers of resilient material with a smaller pressure distribution plate sandwiched between them, thereby providing improved distribution of localized pressure across a broader area of the palm. The smaller dimensions of the pressure distribution plate ensure that the perimeter of the pad remains soft and flexible and that hand and finger mobility are not unduly restricted. Unlike traditional cycling gloves, the present invention also protects the area of the wrist that comes into contact with xe2x80x9croad racingxe2x80x9d style handlebars when the rider is grasping, or leaning on, the brake hoods. Unlike the prior art, the retaining strap configuration of the present invention does not encircle the wrist, thereby allowing the lower end of the pad to move freely with the hand and accommodate comfortably the side-to-side and inward movement of the hand common during cycling.
It is also an object of the present invention to provide a protective pad that can be comfortably worn by itself, in lieu of gloves, or over gloves, if additional protection is desired. Another object is to provide a palm and wrist protector that can be used effectively in activities other than cycling that require hand and wrist protection. Yet another object of the present invention is to provide a protective pad that is comfortable in warm weather, easy to put on and take off, and that is attractive in its combination of simplicity, functionality, and cost.